OMDeffered fail with result category

OMDeferred+FailWithResult.m

@implementation OMDeferred (FailWithResult)

-(void)fail:(NSError *)error withResult:(id)result{
    NSAssert(error, @"Error object should not be nil");
    NSAssert(error.domain, @"Error object should have a domain");
    if(result){
        NSMutableDictionary *newUserInfo = [NSMutableDictionary dictionaryWithDictionary:error.userInfo];
        newUserInfo[ERROR_RESULT_KEY] = result;
        error = [NSError errorWithDomain:error.domain code:error.code userInfo:newUserInfo.copy];
    }
    [self fail:error];
}

@end